- tertiary
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![iciba](/etym/ico/iciba.ico)
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[tertiary 词源字典] - tertiary: see third
[tertiary etymology, tertiary origin, 英语词源] - tertiary (adj.)
![youdao](/etym/ico/youdao.ico)
![iciba](/etym/ico/iciba.ico)
![Dict](/etym/ico/haici.ico)
![YouDict](/etym/ico/youdict.ico)
- 1650s, "of the third order, rank, degree, etc.," from Latin tertiarius "of or pertaining to a third," from tertius "third, a third," from root of tres "three" (see three). The geological sense (with capital T-) of "era after the Mesozoic" (which formerly was called the Secondary) is attested from 1794, after Italian terziari, used in this sense 1760 by Italian geologist Giovanni Arduino (1714-1795).